1. Field of the Invention
This invention relates to a signal processing apparatus, and more particularly to processing of a play list that specifies an image signal reproducing procedure.
2. Description of the Related Art
Conventionally, there are known VTRs as equipment for recording image signals. If the VTR records a new image signal on a tape on which has already been recorded an image signal, the already recorded image signal is erased to record the new image signal. Thus, in reproducing the tape, an image based on the recorded new image signal is reproduced in succession to a part of a previously recorded image for which the image signal is not erased.
On the other hand, there have been recently developed apparatuses that record image data on disk media (hereinafter referred to as “disks”) such as a magneto-optical disk and reproduce the same from the disks. Image signals are generally recorded and reproduced on a file-by-file basis on and from the disk media. Namely, even if an instruction for recording a new image signal on a disk is given at a time point when reproduction of a part of one file is completed, the new image signal is not recorded over the file having been reproduced as is the case with VTRS, but is recorded as a new file.
For this reason, these apparatuses using disk media utilize a play list technique in order to insert one file in an image signal of another file and reproduce the same. This play list is a file that is capable of freely specifying the procedure for reproducing information signals recorded on a disk. For example, the play list is capable of specifying the reproducing procedure such that “after reproduction of a file A from the top thereof for 10 seconds, a file B is reproduced from a position that is advanced from the top of the file B by 15 seconds”. In this case, there is no necessity of processing original information signals of the files A and B.
By utilizing the play list technique as described above, it is possible to insert an image signal at a desired position and reproduced the same as in VTRs.
In VTRs, however, if a tape is edited such that a new scene is reproduced in succession to a previously recorded scene, the new scene must be overwritten on a trailing part of the previously recorded scene. Consequently, an already recorded image signal for the trailing part of the previously recorded scene is erased.
Further, when an image signal is inserted, to provide a space for recording the image signal, image signals for scenes before and after a position in which the image signal is to be inserted are once moved to another recording medium, and then the image signal to be inserted and the image signals for the scenes before and after the position are recorded onto the original recording medium. Moreover, when fade-in or fade-out is applied to a previously recorded scene, to provide a space for recording an image signal for a scene to be newly recorded, an image signal for the previously recorded scene and the image signal for the scene to be newly recorded are once moved to another recording medium, and then the image signal for the previously recorded scene and the image signal for the scene to be newly recorded are recorded onto the original recording medium such that the new scene is superimposed on the previously recorded scene.
Thus, to insert or cross-fade an image signal, it is necessary to carry out edition by once moving the relevant image signals to another recording medium and then again recording these image signals onto the original recording medium. It is therefore necessary to prepare two recording and reproducing apparatuses.
Further, even if an apparatus using a disk as a recording medium utilizes the play list technique, a play list must be edited after recording all information signals as materials. A user who is accustomed to recording by the VTR, however, cannot easily edit a play list after shooting.